Patent US4072534A successfully refreshed from Google Patents.
US4072534A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Super sulphate cement reinforced with glass fibers
Assignee: National Research Development Corp UK
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Filing: 1975-12-23
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Granted: 1978-02-07
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Expires: 1995-12-23
Abstract
Abstract Glass fiber cementitious composites of improved durability comprise fibers of an alkali-resistant glass containing zirconia or stannia in combination with a supersulphate cement. The invention also includes processes for the production of such composites with particular reference to the production of molded or cast products by a modification in which self-supporting green products are produced at an early stage.
Inventors
- 👤 Jack F. Ryder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:46
CPC Classifications
C; C03; C03C; C03C13/00; C03C13/001; C03C13/002; C04; C04B; C04B14/00; C04B14/38; C04B14/42; C04B28/00; C04B28/02; C04B28/08
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
74 words
A process for preparing a glass fibre cementitious composite comprising alkali-resistant glass fibres and supersulphate cement which comprises admixing from 0.5 to 10% by weight, based on the glass fibre/wet cement mix, of said alkali-resistant glass fibres in a supersulphate cement matrix, said alkali-resistant glass fibres comprising from 5 to 20% by weight of a material selected from the class consisting of zirconia and stannia and from 60 to 80% by weight of silica.
Claim 2
Dependent Claim
74 words
A process for preparing a glass fibre cementitious composite comprising alkali-resistant glass fibres and supersulphate cement which comprises admixing from 0.5 to 10% by weight, based on the glass fibre/wet cement mix, of said alkali-resistant glass fibres in a supersulphate cement matrix, said alkali-resistant glass fibres comprising from 5 to 20% by weight of a material selected from the class consisting of zirconia and stannia and from 60 to 80% by weight of silica.
Claim 3
Dependent Claim
53 words
A process according to claim 1 for the production of moulded or cast cementitious composites, in which the supersulphate cement initially comprises calcium sulphate hemihydrate and green products are removed from the moulds or casts when they become self-supporting as a result of the first set due to the hydration of the hemihydrate.
Claim 4
Dependent Claim
31 words
A process according to claim 2, in which the green products are removed from the moulds or casts less than 2 hours after introduction of the glass fibre/wet cement mix thereto.
Claim 5
Dependent Claim
62 words
A glass fibre cementitious product comprising supersulphate cement and alkali-resistant glass fibres containing from 0.5 to 10% by weight of fibres based on the glass fibre/wet cement mix, in which said alkali-resistant glass fibres comprise from 5 to 20% by weight of a material selected from the class consisting of zirconia and stannia and from 60 to 80% by weight of silica.
Claim 6
Dependent Claim
62 words
A glass fibre cementitious product comprising supersulphate cement and alkali-resistant glass fibres containing from 0.5 to 10% by weight of fibres based on the glass fibre/wet cement mix, in which said alkali-resistant glass fibres comprise from 5 to 20% by weight of a material selected from the class consisting of zirconia and stannia and from 60 to 80% by weight of silica.
Claim 7
Dependent Claim
32 words
The cementitious product of claim 4, wherein the supersulphate cement is derived from the hydraulic setting reaction of a reactive glassy material comprising silica, alumina and calcia, with a calcium sulphate activator.
Claim 8
Dependent Claim
39 words
The cementitious product of claim 5, wherein the supersulphate cement is derived from the hydraulic setting reaction of a dry cement mix comprising a calcium sulphate activator at least part of which is in the form of the hemihydrate.
Claim 9
Dependent Claim
13 words
The cementitious product of claim 6, wherein the activator is calcium sulfate hemihydrate.
Claim 10
Dependent Claim
15 words
The cementitious product of claim 5, wherein the glassy material is granulated blast furnace slag.
Claim 11
Dependent Claim
44 words
The cementitious product of claim 8, wherein the granulated blast furnace slag comprises from about 40 to about 50% by weight of calcia, from about 30 to about 40% by weight of silica and from about 8 to about 18% by weight of alumina.
Claim 12
Dependent Claim
55 words
The cementitious product of claim 4, wherein the supersulphate cement is derived from the hydraulic setting reaction of a dry cement mix comprising at least 70% by weight of reactive glassy material, from about 7 to about 25% by weight of calcium sulphate activator, and up to about 5% by weight of an alkaline accelerator.
Claim 13
Dependent Claim
21 words
The cementitious product of claim 10, wherein the alkaline accelerator is selected from the group consisting of Portland cement and lime.
Claim 14
Dependent Claim
51 words
The cementitious product of claim 10 in which the dry cement mix comprises from about 80% to about 85% by weight of reactive glassy material, from about 10 to about 15% by weight of calcium sulphate activator and the balance an accelerator from the group consisting of Portland cement and lime.
Claim 15
Dependent Claim
21 words
The cementitious product of claim 12, wherein the calcium sulphate activator comprises at least 7% by weight of calcium sulphate hemihydrate.
Claim 16
Dependent Claim
21 words
The cementitious product of claim 4, in which the alkali-resistant siliceous glass fibres contain at least 8% by weight of stannia.
Claim 17
Dependent Claim
20 words
The cementitious product of claim 4, in which the alkali-resistant glass fibres contain at least 7% by weight of zirconia.
Claim 18
Dependent Claim
39 words
The cementitious product of claim 4, in which the siliceous glass fibres also comprise about 10 to about 20% of a network modifier selected from the group consisting of alkali metal oxide, alkaline earth metal oxide and zinc oxide.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-06 | 1981-08-08 | 1982-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-06 | 1985-08-08 | 1986-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-06 | 1989-08-08 | 1990-02-07 | $7700.00 | Window Closed / Lapsed |